1. Field of the Invention
This invention relates to a method for forming a connection device of highly integrated semiconductor device, and more particularly to, a method for forming a connection device of highly integrated semiconductor device in which when one conductive material layer is selectively connected to another conductive material layer which is positioned on the one conductive layer or below the one conductive layer, a portion of an insulating layer formed on the underlying conductive material layer is etched to form a contact hole, and the conductive material layers are electrically connected by depositing a conductive material layer on the entire surface after forming insulating film spacers on the side wall of the contact hole to insulate the conductive material layers from the other electrode, thereby reducing the area of cell of semiconductor device.
Generally, in manufacturing an integrated circuit semiconductor device, in order to electrically connect a conductive material layer to another conductive material layer underlying the one conductive material layer, a portion of an insulating layer formed between the one conductive material layer and the another conducive material layer is etched to form a contact hole through which an electrical connection is accomplished. Regions where such a contact hole is formed are, for example, on a diffusion region in the silicon substrate, on a gate electrode and on a conductive material layer for internal connection line.
In order to form the contact hole in such regions, a plurality of mask patterning process steps must be performed utilizing a mask for patterning the conductive material layer to be electrically connected, a contact mask for forming a contact hole and a mask for patterning the conductive material layer deposited in the contact hole. The alignment of such masks must be performed in accordance with design rules for a semiconductor device.
2. Information Disclosure Statement
In the prior art a contact hole is obtained by etching a portion of an insulating layer formed on a conductive material layer to be contacted by lithographic etching technology. If a connection device for a semiconductor device is formed utilizing the prior art method for forming the contact hole, the alignment for each mask must be designed as described above.
For example, as illustrated in FIG. 1A and 1B, in order to form a connection device for a semiconductor device to electrically connect a bit line 8A to MOSFET 20A, 20B, when a contact hole is formed on a source electrode 4 of MOSFET 20A, 20B, the width "w" between the contact mask C and gate electrodes 3A, 3B which are located proximate both ends of the source electrode 4 must be as long as the distance which must be maintained considering a thickness of insulating layer 5 to insulate the bit line 8A from the gate electrodes 3A and 3B, a minimum misalignment tolerance required for mask patterning process and a critical dimension loss occurred during the lithographic etching process. Otherwise, a current leakage may occur or it may cause a short circuit between the bit line 8A and the gate electrodes 3A, 3B, thereby resulting in the failure of the semiconductor device, or since the thickness of the insulating layer between the gate electrode 3A, 3B and the bit line 8A becomes thin, the insulating layer may be broken down during the operation of the semiconductor device, so that the semiconductor device may not be operated.
Also, as illustrated in FIG. 4A and 4B, if a connection device for semiconductor device is made by forming a contact hole 14 on an internal connection line 9A which connects device to device, the width "w" of the internal connection line 9A must be maintained as long as the distance which should be retained considering a width Cx of the contact mask C, the mask misalignment tolerance and the critical dimension loss, that is, at least Cx+2a is needed, wherein Cx is the width of the contact mask C and "a" is the misalignment tolerance and the critical dimension loss. As described above, when the contact hole 14 is formed according to the prior art method, the width "w" of the internal connection line 9A positioned where the contact hole is formed should be larger than the width Cx of the contact mask C, so the integrity of semiconductor device decreases.
Accordingly, it is an object of the present invention to solve the problems presented in the prior art method for forming the connection device for semiconductor device, and to provide a method for forming a connection device for a semiconductor device, which comprises forming insulating film spacers on the side walls of contact hole after the contact hole is formed on a portion of an insulating layer formed on one conductive material layer, and depositing another conductive material layer to be electrically connected to the one conductive material layer on the entire surface.